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Bismuth trioxide

Bismuth(III) oxide
Bismuth trioxide
AlfaBi2O3structure.jpg
Names
IUPAC names
Bismuth trioxide
Bismuth(III) oxide
Bismite (mineral)
Other names
Bismite, bismuth sesquioxide
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.013.759
UNII
Properties
Bi2O3
Molar mass 465.96 g/mol
Appearance yellow crystals or powder
Odor odorless
Density 8.90 g/cm3, solid
Melting point 817 °C (1,503 °F; 1,090 K)
Boiling point 1,890 °C (3,430 °F; 2,160 K)
insoluble
Solubility soluble in acids
-83.0·10−6 cm3/mol
Structure
monoclinic, mP20,
Space group P21/c (No 14)
pseudo-octahedral
Hazards
Safety data sheet See: data page
MallBaker MSDS
not listed
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point Non-flammable
Related compounds
Other anions
Bismuth trisulfide
Other cations
Arsenic trioxide
Antimony trioxide
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Thermodynamic
data
Phase behaviour
solid–liquid–gas
UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Bismuth(III) oxide is perhaps the most industrially important compound of bismuth. It is also a common starting point for bismuth chemistry. It is found naturally as the mineral bismite (monoclinic) and sphaerobismoite (tetragonal, much more rare), but it is usually obtained as a by-product of the smelting of copper and lead ores. Bismuth trioxide is commonly used to produce the "Dragon's eggs" effect in fireworks, as a replacement of red lead.

The structures adopted by Bi2O3 differ substantially from those of arsenic(III) oxide, As2O3, and antimony(III) oxide, Sb2O3.

Bismuth oxide, Bi2O3 has five crystallographic polymorphs. The room temperature phase, α-Bi2O3 has a monoclinic crystal structure. There are three high temperature phases, a tetragonal β-phase, a body-centred cubic γ-phase, a cubic δ-Bi2O3 phase and an ε- phase. The room temperature α-phase has a complex structure with layers of oxygen atoms with layers of bismuth atoms between them. The bismuth atoms are in two different environments which can be described as distorted 6 and 5 coordinate respectively.

β-Bi2O3 has a structure related to fluorite.

γ-Bi2O3 has a structure related to that of Bi12SiO20 (a sillenite), where a fraction of the Bi atoms occupy the position occupied by SiIV, and may be written as Bi12Bi0.8O19.2.


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